fix: staticlookup inside call

[alexander-akait]

fixes #201

[alexander-akait]

Looks read_expr is invalid here, what better call?

[ichiriac]

it's not so clear, here an extract from the grammar :

https://github.com/php/php-src/blob/master/Zend/zend_language_parser.y#L1175

member_name:
		identifier { $$ = $1; }
	|	'{' expr '}'	{ $$ = $2; }
	|	simple_variable	{ $$ = zend_ast_create(ZEND_AST_VAR, $1); }
;

simple_variable:
		T_VARIABLE			{ $$ = $1; }
	|	'$' '{' expr '}'	{ $$ = $3; }
	|	'$' simple_variable	{ $$ = zend_ast_create(ZEND_AST_VAR, $2); }
;

function_call:
		name argument_list
			{ $$ = zend_ast_create(ZEND_AST_CALL, $1, $2); }
	|	class_name T_PAAMAYIM_NEKUDOTAYIM member_name argument_list
			{ $$ = zend_ast_create(ZEND_AST_STATIC_CALL, $1, $3, $4); }
	|	variable_class_name T_PAAMAYIM_NEKUDOTAYIM member_name argument_list
			{ $$ = zend_ast_create(ZEND_AST_STATIC_CALL, $1, $3, $4); }
	|	callable_expr argument_list
			{ $$ = zend_ast_create(ZEND_AST_CALL, $1, $2); }
;

and function_call is used by callable_variable, whic used by variable, used by expr, so that's the right place - I'll checkout and play with the code

[ichiriac]

everything is correct, but I see an extra statement. Here a sample error code :

Order::{call()};
SyntaxError: Parse Error : syntax error, unexpected ';', expecting '(' on line 1

Come from this L99 :
https://github.com/glayzzle/php-parser/pull/225/files/a284ac035ed8f7d57e97c46a94f6aa0cc7467f17#diff-bb9fff60e32f00c7312e3788510fe2acR99

As you can see from the specs, you have handled the '{' expr '}' :

member_name:
		identifier { $$ = $1; }
	|	'{' expr '}'	{ $$ = $2; }
	|	simple_variable	{ $$ = zend_ast_create(ZEND_AST_VAR, $1); }
;

[ichiriac]

Damn, after checking with PHP 7.2, here the result :

ioan@devbox:~/Documents/glayzzle/php-parser$ php -r "Order::{call()};"
PHP Parse error:  syntax error, unexpected ';', expecting '(' in Command line code on line 1

Need to digg more into this 👎

[ichiriac]

Ok, just for information, in order to check what is wrong, I make a search on the zend parser language on the token that make static lookups T_PAAMAYIM_NEKUDOTAYIM and try to understand what can come next - Im' doing this to understand allowed syntax.

Here the results :

class_name T_PAAMAYIM_NEKUDOTAYIM simple_variable
variable_class_name T_PAAMAYIM_NEKUDOTAYIM simple_variable
new_variable T_PAAMAYIM_NEKUDOTAYIM simple_variable
name T_PAAMAYIM_NEKUDOTAYIM identifier
class_name T_PAAMAYIM_NEKUDOTAYIM member_name argument_list
variable_class_name T_PAAMAYIM_NEKUDOTAYIM member_name argument_list
class_name T_PAAMAYIM_NEKUDOTAYIM identifier
variable_class_name T_PAAMAYIM_NEKUDOTAYIM identifier

We are in a member_name related expression, before your change member_name was either an identifier or a simple_variable, so no mandatory argument_list.

Now with the expr introduction, member_name has an differentiation, identier or simple_variable (previous code) can run just as before without a constraint on calling expression, but now, you need a call statement just after the expr, because of member_name argument_list.

So your expect ( statement was a good way to force the parser to validate the syntax and continue the AST with a call node.

Now in order to be sure if you don't introduce a miss-behavior you need to check the read_static_getter helper usage into the parser and also to check the member_name from the php source.

In php-parser, it's used by read_class_name_reference, read_scalar, read_variable

In php yaccs file : function_call, which is itself called from callable_variable, which in turn is called from callable_expr, variable (equivalent of our read_variable)

So I conclude that read_class_name_reference + read_scalar may introduce problems, need to digg more.

Checking the read_scallar function I found a comment about https://github.com/php/php-src/blob/master/Zend/zend_language_parser.y#L1151 pointing to nothing as I did not include the commit-id on links 👎 - so I need to digg with the opening token T_CONSTANT_ENCAPSED_STRING, used by dereferencable_scalar -> scallar, dereferencable, callable_expr. As callable_expr is used to trigger a function_call we are good with this one.

The same for the other, the read_new_expr is the only reference to this one, so I go to the yaccs definition, and find that corresponds to the new_expr definition defined as :

new_expr:
		T_NEW class_name_reference ctor_arguments
			{ $$ = zend_ast_create(ZEND_AST_NEW, $2, $3); }
	|	T_NEW anonymous_class
			{ $$ = $2; }
;

Our block of code concerns onlye the class_name_reference ctor_arguments part, and here the definition of the class_name_reference

class_name_reference:
		class_name		{ $$ = $1; }
	|	new_variable	{ $$ = $1; }
;
new_variable:
		simple_variable
			{ $$ = zend_ast_create(ZEND_AST_VAR, $1); }
	|	new_variable '[' optional_expr ']'
			{ $$ = zend_ast_create(ZEND_AST_DIM, $1, $3); }
	|	new_variable '{' expr '}'
			{ $$ = zend_ast_create(ZEND_AST_DIM, $1, $3); }
	|	new_variable T_OBJECT_OPERATOR property_name
			{ $$ = zend_ast_create(ZEND_AST_PROP, $1, $3); }
	|	class_name T_PAAMAYIM_NEKUDOTAYIM simple_variable
			{ $$ = zend_ast_create(ZEND_AST_STATIC_PROP, $1, $3); }
	|	new_variable T_PAAMAYIM_NEKUDOTAYIM simple_variable
			{ $$ = zend_ast_create(ZEND_AST_STATIC_PROP, $1, $3); }
;
simple_variable:
		T_VARIABLE			{ $$ = $1; }
	|	'$' '{' expr '}'	{ $$ = $3; }
	|	'$' simple_variable	{ $$ = zend_ast_create(ZEND_AST_VAR, $2); }
;

As you can see here, T_PAAMAYIM_NEKUDOTAYIM must be handled in our case, but just followed with simple_variable which excludes an identifier or an '{' expr '}'

[ichiriac]

Here our parser is just not enough strict and will parse these extra syntax, and PHP not :

ioan@devbox:~/Documents/glayzzle/php-parser$ php -r "new Foo::{call()}();"
PHP Parse error:  syntax error, unexpected '{', expecting variable (T_VARIABLE) or '$' in Command line code on line 1
ioan@devbox:~/Documents/glayzzle/php-parser$ php -r "new Foo::call();"
PHP Parse error:  syntax error, unexpected 'call' (T_STRING), expecting variable (T_VARIABLE) or '$' in Command line code on line 1
ioan@devbox:~/Documents/glayzzle/php-parser$ php -r "new Foo::call;"
PHP Parse error:  syntax error, unexpected 'call' (T_STRING), expecting variable (T_VARIABLE) or '$' in Command line code on line 1
ioan@devbox:~/Documents/glayzzle/php-parser$ php -r "new Foo::$bar;"
PHP Parse error:  syntax error, unexpected ';', expecting variable (T_VARIABLE) or '$' in Command line code on line 1